A Knee Lift, alternatively called a Free Hand System (FHS), is a bar or lever that latches into the bottom right front of a sewing machine. Because the bar is bent to extend beyond the stitching surface, three things happen with a nudge of your knee: The presser foot is raised according to the amount of pressure applied to the Knee Lift. This keeps both hands free for work. Certain sewers adore the knee control, which enables them to raise their knee and modify the machine's beginning, stopping, and pace.
When working with thick or bulky fabrics, or when performing complex stitching maneuvers, foot and knee lifters are helpful on a sewing machine because they allow the user to lift the presser foot without using their hands. Fabric is held in place during sewing by the presser foot; various sewing techniques require lifting the presser foot temporarily. These include inserting zippers, turning corners, and changing the direction of stitching. The presser foot can be lifted with the knee lifter, which is typically a bar situated beneath the sewing machine table, freeing up the hands to direct the fabric. Smoother and even stitching is the result of the user's increased ability to control the fabric and direct it through the machine without having to use both hands.